Replace static DICOM test data with minimal dynamic content

[rkm]

Proposed Changes

Many of our integration tests depend on one or more specific DICOM files which are cached in the repo. This PR replaces them with dynamically generated content.

The next step is to enable the use of MockFileSystem where sensible so that our tests don't require so much I/O.

Types of changes

• Bugfix (non-breaking change which fixes an issue)
• New Feature (non-breaking change which adds functionality)
• Breaking Change (fix or feature that would cause existing functionality to not work as expected)
• Documentation-Only Update (if none of the other choices apply)
  • In this case, ensure that the message of the head commit from the source branch is prefixed with [skip ci]

Checklist

By opening this PR, I confirm that I have:

• Reviewed the contributing guidelines for this repository
• Ensured that the PR branch is in sync with the target branch (i.e. it is automatically merge-able)
• Updated any relevant API documentation
• Created or updated any tests if relevant
• Created a news file
  • NOTE: This must include any changes to any of the following files: default.yaml, any of the RabbitMQ server configurations, GlobalOptions.cs
• Listed myself in the CONTRIBUTORS file 🚀
• Requested a review by the @SMI/Reviewers team

Issues

Closes #2019

[codecov]

Codecov Report

Attention: Patch coverage is 57.14286% with 3 lines in your changes missing coverage. Please review.

Project coverage is 64.07%. Comparing base (c00eabd) to head (56b0544).

Files	Patch %	Lines
...ces/Microservices/DicomTagReader/DicomTagReader.cs	0.00%	2 Missing ⚠️
...ervices/DicomTagReader/DicomTagReaderCliOptions.cs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1918      +/-   ##
==========================================
- Coverage   64.07%   64.07%   -0.01%     
==========================================
  Files         177      177              
  Lines        6525     6527       +2     
  Branches      968      969       +1     
==========================================
+ Hits         4181     4182       +1     
- Misses       2057     2058       +1     
  Partials      287      287              

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